Explain why the Senate can function effectively with a far more informal atmosphere then the House of Representatives?
This statement has been truer in the past than it is in today's more polarized atmosphere. However, the Senate typically can do this because of the more "collegial" atmosphere that is possible in the Senate.
Senators typically get to know one another much better the Representatives do. There are many fewer Senators and they serve much longer terms than the Representatives do. This means that they have many more chances to get to know one another. In addition, they represent much bigger areas and are therefore usually less able to hold extreme views because they have to appeal to a broader range of voters than Representatives do. For these reasons, they have typically been able to work more consensually with one another even in a less formal and structured house.